A device for synthesizing a magnetic material alloy coating film based on an electric explosion method

Abstract

The application relates to a magnetic material alloy coating film synthesizing device based on an electric explosion method and belongs to the technical field of pulse power. The purpose of the application is to provide a magnetic material alloy coating film synthesizing device based on an electric explosion method. The device uniformly winds ferromagnetic metals Fe, Co and Ni into a three-strand wire and embeds the three-strand wire into a semi-closed medium pipe. The pipe can improve the deposition energy in the electric explosion process of the metal wire. In addition, the pipe can significantly improve the metal vapor injection speed and obtain a specific injection direction. Uniformly wound power coils and a direction changing device are arranged on the metal vapor injection track, so that the device can adjust the direction of the magnetic field and make the ionized metal vapor after explosion experience different directions of magnetization.

Description

Technical Field

[0001] This invention relates to a device for synthesizing magnetic material alloy coating thin films based on an electro-explosion method, belonging to the field of pulsed power technology. Background Technology

[0002] The anisotropic magnetoresistive (AMR) effect of magnetic thin films is the foundation for magnetoresistive sensors. Its working principle can be summarized as follows: when a magnetically conductive thin film is placed in an external magnetic field, the film's resistance changes. Magnetoresistive sensors based on magnetic thin films utilize the Wheatstone bridge principle. When a current flows through the thin film and an external magnetic field is applied, the magnitude of the applied magnetic field can be determined by the change in resistance in the bridge arms. Magnetoresistive sensors also possess advantages such as strong shock resistance, strong anti-interference capability, high sensitivity, and low cost. The strength of the magnetoresistive effect is closely related to the magnetic thin film structure. When the film thickness is reduced to the nanometer scale and a multilayer structure is formed, its magnetoresistance is much higher than that of AMR magnetoresistance, hence it is also called the giant magnetoresistive (GMR) effect. Magnetoresistive sensors based on the giant magnetoresistive effect still use the Wheatstone bridge structure for measurement, inheriting the advantages of AMR sensors while possessing a higher rate of magnetoresistance change, thus making them more suitable for detecting weak magnetic fields. In summary, the properties of the magnetic material thin films significantly affect the superior performance of magnetoresistive sensors, and the methods for preparing high-quality magnetic material thin films need further exploration and improvement.

[0003] Common coating preparation methods can be broadly classified into three categories: solid-phase, liquid-phase, and vapor-phase methods. Common methods include electroplating, electroless plating, thermal / cold spraying, chemical vapor deposition, and physical vapor deposition. The appropriate spraying method is usually selected based on the coating's application environment and function. However, all of these methods have certain problems in practical applications, such as environmental pollution (electroplating, electroless plating) and issues with preparation efficiency and cost (physical / chemical vapor deposition). Electrical explosion of wires (EEW) involves injecting a pulsed current with specific parameters into a metal conductor (wire). Under Joule heating, the metal load undergoes rapid phase changes, quickly transitioning from solid to liquid, gas, and plasma phases. The entire process can be completed within microseconds. The conductor load heating temperature can reach over 10,000 degrees Celsius, and the expansion velocity of the explosion products can reach hundreds of meters per second, making it a special "one-step" thermal spraying method. It features extremely high reaction temperatures and cooling rates (up to 10...). 10The high spraying speed (K / s) produces spherical nanoparticles with diameters of 5-100 nm, providing a foundation for the preparation of uniform and fine nanoscale coatings. The extremely high spraying speed ensures excellent adhesion between the thin film coating and the substrate. The electro-explosion method is simple and efficient, with low requirements for the raw materials used to prepare the nanopowders, only requiring them to be conductors or have a metal coating, greatly reducing manufacturing costs. Pure metal nanocoatings can be prepared in an inert gas atmosphere. Simultaneously, the electro-explosion method can achieve single-shot triggering of multiple metal wires of different materials, making it possible to prepare multi-component alloy nanofilm coatings. Due to the complexity of the electro-explosion process, amorphous nanoparticles and gradient-distributed special alloy coatings can also be obtained under suitable parameters, which broadens the path for preparing functional alloy nanocoatings using the electro-explosion method. Summary of the Invention

[0004] The purpose of this invention is to provide a device for synthesizing magnetic material alloy coating films based on an electro-explosion method. This device uniformly winds ferromagnetic metals Fe, Co, and Ni into a three-stranded wire, which is then nested within a semi-enclosed dielectric tube. This tube can increase the deposition energy during the electro-explosion process of the metal wire and significantly improve the metal vapor ejection speed and achieve a specific ejection direction. A uniformly wound energized coil and a direction-changing device are installed along the metal vapor ejection trajectory to adjust the magnetic field direction, causing the ionized metal vapor after the explosion to undergo magnetization in different directions.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A device for synthesizing magnetic material alloy coating thin films based on the electro-explosion method includes an electro-explosion cavity, a high-voltage electrode, a ground electrode, an insulator, a secondary transfer electrode, a semi-enclosed dielectric tube, a metal stranded wire load, a thin film alloy deposition substrate, a Helmholtz coil, a mechanical cantilever, an exhaust port, and an air inlet.

[0007] The secondary transition electrode, semi-enclosed dielectric tube, metal stranded wire load, thin film alloy deposition substrate, Helmholtz coil, and mechanical cantilever are placed in the electric explosion cavity. The high-voltage electrode and ground electrode are coaxially nested in an insulator, which is connected to the electric explosion cavity and extends into its interior. The secondary transition electrode is an extension of the high-voltage electrode and ground electrode and is used to fix the semi-enclosed dielectric tube and metal stranded wire load. The thin film alloy deposition substrate is fixed to the secondary transition electrode connected to the ground electrode. The Helmholtz coil is connected to the electric explosion cavity through the mechanical cantilever and its direction is adjustable. The magnetic field region provided by the Helmholtz coil covers the secondary transition electrode, semi-enclosed dielectric tube, metal stranded wire load, and thin film alloy deposition substrate. The exhaust port and intake port are located on both sides of the electric explosion cavity and are used to control the vacuum level and supply the working gas within the electric explosion cavity.

[0008] The electric explosion chamber is made of stainless steel, with sandblasted inner surface and observation windows on the walls to facilitate observation and diagnosis of the electric explosion process.

[0009] The high-voltage electrode and the grounding electrode are stainless steel pillars, which are respectively connected to the core of the double-shielded coaxial high-voltage cable and the grounding outer sheath. The grounding metal braided mesh wrapped on the outer layer can effectively prevent the electromagnetic radiation generated by the strong pulse current from affecting the discharge device and diagnostic equipment.

[0010] The insulator is made of black nylon material, which separates the high-voltage electrode post from the cavity to prevent the high-voltage electrode from connecting with the cavity or from breaking down, creeping and other phenomena. The surface of the insulator has a spiral structure, which can effectively increase the insulation strength. At the same time, the nylon material has excellent mechanical hardness and can resist the strong shock wave generated by the electric explosion.

[0011] The secondary transfer electrode is an extension of the high-voltage electrode and the ground electrode. It consists of stainless steel threaded columns and copper cylindrical electrodes. It is used to fix the semi-enclosed dielectric tube and the metal wire load, and the length of the metal wire load can be changed at will.

[0012] The semi-enclosed dielectric tube is a cylindrical semi-enclosed dielectric tube made of acrylonitrile-butadiene-styrene copolymer. Metal stranded wires are coaxially nested inside the dielectric tube. One end of the dielectric tube is tightly attached to the copper electrode, and the other end is open and faces the substrate silicon wafer to guide the high-speed ejected metal vapor / plasma jet.

[0013] The metal stranded wire load is made of three ferromagnetic metal wires of Fe, Co and Ni. The three metal wires are of the same length, have the same number of turns and the same distance between turns. The metal wires are tightly attached to each other, which facilitates better mixing of different metal wires during the explosion and plasma process.

[0014] The thin film alloy deposition substrate is a single-crystal silicon wafer; silicon wafers, as substrate materials, are easy to use directly for subsequent characterization by equipment such as SEM, EDS, XRD, and XPS without additional transfer steps, ensuring the originality of the sample; after obtaining a thin film with ideal characteristics, the substrate can be changed to any target object that needs to be sprayed.

[0015] A Helmholtz coil is a pair of identical, parallel, and coaxial coils, each powered by a separate DC power supply. The distance D between the coils is exactly equal to the coil diameter d, ensuring a uniform and constant unidirectional magnetic field within region D.

[0016] The mechanical cantilever is connected to two Helmholtz coils respectively. The mechanical cantilever is equipped with a direction adjustment knob and a telescopic rod to adjust the coil's axis direction within the range of 0-90°, thereby obtaining magnetic fields in different directions, which facilitates the magnetization of metal nanoparticles in different directions.

[0017] The evacuation port and the inlet port are connected to the vacuum pump and the Ar gas cylinder, respectively. First, the vacuum pump evacuates the cavity to a relatively low vacuum environment (~100 Pa level). Ar gas is then introduced into the cavity through the inlet port to restore the cavity to atmospheric pressure. At this time, the cavity is an Ar gas environment, which can effectively prevent the oxidation of the products of the electrical explosion.

[0018] Working Process: The entire electro-explosion process occurs within the electro-explosion cavity. The high-voltage electrode and the ground electrode are connected to the pulse source system via a coaxial high-voltage cable, with the high-voltage electrode connected to the inner core of the coaxial high-voltage cable and the ground electrode connected to the outer sheath. The pulse source system consists of a DC high-voltage power supply, a pulse capacitor, and a spark switch. When the DC high-voltage power supply charges the pulse capacitor to the required voltage, the pulse current flows through the high-voltage electrode, the ground electrode, and the secondary transfer electrode, passing through the metal stranded wire load to form a current loop, thereby driving the metal stranded wire electro-explosion. The material generated by the electro-explosion forms a directional jet of metal through a semi-enclosed dielectric tube, forming an alloy film on the thin film alloy deposition substrate. The Helmholtz coil continuously provides a uniform magnetic field during this process, covering the secondary transfer electrode, the semi-enclosed dielectric tube, the metal stranded wire load, and the thin film alloy deposition substrate. The mechanical cantilever connected to the Helmholtz coil can rotate the coil direction, thereby controlling the direction of the magnetic field and magnetizing the metal nanoparticles in different directions during the thin film deposition process.

[0019] Beneficial effects:

[0020] 1. The present invention discloses a magnetic material alloy coating film synthesis device based on the electro-explosion method. The metal strands are made of ferromagnetic materials Fe, Co and Ni. The three metal wires are evenly wound with the same total length, the same number of turns and the same distance between turns. The metal wires are tightly attached to each other. The winding structure can make different metal wires mix better during the explosion and plasma process.

[0021] 2. The present invention discloses a magnetic material alloy coating film synthesis device based on electro-explosion method, which nests uniformly wound metal wires into a semi-enclosed medium tube, thereby improving the deposition energy during the electro-explosion process of the metal wires and obtaining directional injection of metal vapor.

[0022] 3. The present invention discloses a magnetic material alloy coating film synthesis device based on the electro-explosion method, wherein a uniform, unidirectional constant magnetic field is set between the nozzle and the silicon wafer substrate, which can magnetize the nanoparticles that are condensed into nuclei by electro-explosion vapor before the film coating is formed.

[0023] 4. The present invention discloses a magnetic material alloy coating film synthesis device based on the electro-explosion method. The axial direction of the Helmholtz coil can be changed within 0-90° by a mechanical device to provide magnetic fields in different directions. Therefore, the electro-explosion nanoparticles can be magnetized in different directions to obtain thin film coatings with different magnetic properties. Attached Figure Description

[0024] Figure 1 A schematic diagram of a magnetic material alloy coating thin film synthesis device based on the electro-explosion method disclosed in this invention;

[0025] Wherein: 1—Electro-explosion cavity, 2—High voltage electrode, 3—Ground electrode, 4—Insulator, 5—Secondary transfer electrode, 6—Semi-enclosed dielectric tube, 7—Metal stranded wire load, 8—Thin film alloy deposition substrate, 9—Helmholtz coil, 10—Mechanical cantilever, 11—Exhaust port, 12—Inlet port. Detailed Implementation

[0026] To better illustrate the purpose and advantages of the present invention, the invention will be further described below in conjunction with the accompanying drawings and examples.

[0027] Example 1:

[0028] like Figure 1 As shown in this embodiment, a magnetic material alloy coating thin film synthesis device based on the electro-explosion method is disclosed, including an electro-explosion chamber 1, a high-voltage electrode 2, a ground electrode 3, an insulator 4, a secondary transfer electrode 5, a semi-enclosed dielectric tube 6, a metal stranded wire load 7, a thin film alloy deposition substrate 8, a Helmholtz coil 9, a mechanical cantilever 10, an exhaust port 11, and an intake port 12. The secondary transfer electrode 5, semi-enclosed dielectric tube 6, metal stranded wire load 7, thin film alloy deposition substrate 8, Helmholtz coil 9, and mechanical cantilever 10 are placed within the electro-explosion chamber 1. The high-voltage electrode 2 and the ground electrode 3 are coaxially nested within the insulator 4, which is connected to and extends into the electro-explosion chamber 1. The secondary transfer electrode 5 is an extension of the high-voltage electrode and the ground electrode, used to fix the semi-enclosed dielectric tube 6 and the metal stranded wire load 7. The thin film alloy deposition substrate 8 is fixed to the secondary transfer electrode 5, which is connected to the ground electrode. The Helmholtz coil 9 is connected to the electric explosion chamber 1 via a mechanical cantilever 10, and its direction is adjustable. The magnetic field region provided by the Helmholtz coil 9 covers the secondary transfer electrode 5, the semi-enclosed dielectric tube 6, the metal stranded wire load 7, and the thin film alloy deposition substrate 8. The exhaust port 11 and the inlet port 12 are located on both sides of the electric explosion chamber 1, respectively, and are used to control the vacuum level and supply the working gas within the electric explosion chamber 1.

[0029] The electric explosion chamber 1 is made of stainless steel, with sandblasted inner surface and observation windows on the walls to facilitate observation and diagnosis of the electric explosion process.

[0030] The high-voltage electrode 2 and the grounding electrode 3 are stainless steel pillars, which are respectively connected to the core of the double-shielded coaxial high-voltage cable and the grounding sheath. The grounding metal braided mesh wrapped on the outer layer can effectively prevent the electromagnetic radiation generated by the strong pulse current from affecting the discharge device and diagnostic equipment.

[0031] Insulator 4 is made of black nylon material, which separates the high-voltage electrode post from the cavity to prevent the high-voltage electrode from connecting with the cavity or from breaking down or creeping. The surface of the insulator has a spiral structure, which can effectively increase the insulation strength. At the same time, the nylon material has excellent mechanical hardness and can resist the strong shock wave generated by the electric explosion.

[0032] The secondary transfer electrode 5 is an extension of the high-voltage electrode 2 and the ground electrode 3. It consists of stainless steel threaded columns and copper cylindrical electrodes. It can be used to fix semi-enclosed dielectric tubes and metal wire loads, and the length of the metal wire load can be changed at will.

[0033] The semi-enclosed dielectric tube 6 is a cylindrical semi-enclosed dielectric tube made of acrylonitrile butadiene styrene copolymer (ABS). A metal stranded wire load is coaxially nested inside the dielectric tube. One end of the dielectric tube is tightly attached to the copper electrode, while the other end is open and faces the substrate silicon wafer to guide the high-speed ejected metal vapor / plasma jet.

[0034] The metal stranded wire load 7 is made of three ferromagnetic metal wires: Fe, Co, and Ni. The three metal wires are of the same length, have the same number of turns, and are spaced at the same distance between turns. The metal wires are tightly bonded together, which facilitates better mixing of the different metal wires during the explosion and plasma processes.

[0035] The thin-film alloy deposition substrate 8 is a square single-crystal silicon wafer measuring 10×10 mm and 0.7 mm thick. The silicon wafer, as the substrate material, can be directly used for subsequent characterization by SEM, EDS, XRD, XPS, and other equipment without additional transfer steps, ensuring the originality of the sample. After obtaining a thin film with ideal characteristics, the substrate can be transformed into any target object requiring coating.

[0036] The Helmholtz coil 9 consists of a pair of identical, parallel, and coaxial coils, each powered by a separate DC power supply. The distance D between the coils is exactly equal to the coil diameter d, ensuring a uniform and constant unidirectional magnetic field within region D.

[0037] The mechanical cantilever 10 is connected to two Helmholtz coils. The mechanical cantilever is equipped with a direction adjustment knob and a telescopic rod, which can adjust the coil's axis direction within the range of 0-90° to obtain magnetic fields in different directions, making it convenient to magnetize metal nanoparticles in different directions.

[0038] The evacuation port 11 and the inlet port 12 are connected to a vacuum pump and an Ar gas cylinder, respectively. First, the vacuum pump evacuates the cavity to a relatively low vacuum environment (on the order of ~100 Pa). Ar gas is then introduced into the cavity through the inlet port 12 to restore the cavity to atmospheric pressure. At this time, the cavity is in an Ar gas environment, which can effectively prevent the oxidation of the products of the electrical explosion.

[0039] Working Process: The entire electro-explosion process occurs within the electro-explosion chamber 1. High-voltage electrode 2 and ground electrode 3 are connected to the pulse source system via a coaxial high-voltage cable, with high-voltage electrode 2 connected to the inner core of the coaxial high-voltage cable and ground electrode connected to the outer sheath. The pulse source system consists of a DC high-voltage power supply, a pulse capacitor, and a spark switch. When the DC high-voltage power supply charges the pulse capacitor to the required voltage, the spark switch controls the pulse current to flow through high-voltage electrode 2, ground electrode 3, and secondary transfer electrode 5, passing through the metal stranded wire load 7 to form a current loop, thereby driving the metal stranded wire electro-explosion. The material generated by the electro-explosion forms a directional jet of metal through the semi-enclosed dielectric tube 6, forming an alloy thin film on the thin film alloy deposition substrate 8. The Helmholtz coil 9 continuously provides a uniform magnetic field during this process, covering the secondary transfer electrode 5, the semi-enclosed dielectric tube 6, the metal stranded wire load 7, and the thin film alloy deposition substrate 8. The mechanical cantilever 10 connected to the Helmholtz coil can rotate the coil, thereby controlling the direction of the magnetic field and magnetizing the metal nanoparticles in different directions during the thin film deposition process.

[0040] The above detailed description further illustrates the purpose, technical solution, and beneficial effects of the invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A device for synthesizing magnetic material alloy coating thin films based on the electro-explosion method, characterized in that: It includes an electric explosion cavity (1), a high-voltage electrode (2), a ground electrode (3), an insulator (4), a secondary transfer electrode (5), a semi-enclosed dielectric tube (6), a metal stranded wire load (7), a thin film alloy deposition substrate (8), a Helmholtz coil (9), a mechanical cantilever (10), an exhaust port (11), and an air inlet (12). The secondary transition electrode (5), semi-enclosed dielectric tube (6), metal stranded wire load (7), thin film alloy deposition substrate (8), Helmholtz coil (9), and mechanical cantilever (10) are placed in the electric explosion cavity (1); the high-voltage electrode (2) and the ground electrode (3) are coaxially nested in the insulator (4), which is connected to the electric explosion cavity (1) and extends into the electric explosion cavity; the secondary transition electrode (5) is an extension of the high-voltage electrode and the ground electrode, used to fix the semi-enclosed dielectric tube (6) and the metal stranded wire load (7); the thin film alloy The deposition substrate (8) is fixed on the secondary transfer electrode (5) connected to the ground electrode; the Helmholtz coil (9) is connected to the electric explosion cavity (1) through the mechanical cantilever (10) and its direction is adjustable. The magnetic field area provided by the Helmholtz coil (9) covers the secondary transfer electrode (5), the semi-enclosed dielectric tube 6, the metal stranded wire load (7) and the thin film alloy deposition substrate (8); the exhaust port (11) and the inlet port (12) are located on both sides of the electric explosion cavity and are used to control the vacuum degree in the electric explosion cavity (1) and supply the working gas.

2. The apparatus for synthesizing magnetic material alloy coating thin films based on the electro-explosion method as described in claim 1, characterized in that: The electric explosion chamber (1) is made of stainless steel, with sandblasting on the inner surface of the chamber and observation windows on the walls to facilitate the observation and diagnosis of the electric explosion process. The high-voltage electrode (2) and the grounding electrode (3) are stainless steel columns, which are respectively connected to the core of the double-shielded coaxial high-voltage cable and the grounding outer sheath. The grounding metal braided mesh wrapped on the outer layer can effectively prevent the electromagnetic radiation generated by the strong pulse current from affecting the discharge device and diagnostic equipment. The insulator (4) is made of black nylon material, which separates the high voltage electrode post from the cavity. The surface of the insulator has a spiral structure, which can effectively increase the insulation strength. At the same time, the nylon material has excellent mechanical hardness and can resist the strong shock wave generated by the electric explosion.

3. The apparatus for synthesizing magnetic material alloy coating thin films based on the electro-explosion method as described in claim 1, characterized in that: The secondary transfer electrode (5) is an extension of the high voltage electrode (2) and the ground electrode (3). It is composed of stainless steel threaded columns and copper cylindrical electrodes, used to fix the semi-enclosed dielectric tube and the metal wire load, and can change the length of the metal wire load at will.

4. The apparatus for synthesizing magnetic material alloy coating thin films based on the electro-explosion method as described in claim 1, characterized in that: The semi-enclosed dielectric tube (6) is a cylindrical semi-enclosed dielectric tube made of acrylonitrile-butadiene-styrene copolymer. The metal strand load is coaxially nested inside the dielectric tube. One end of the dielectric tube is tightly attached to the copper electrode, and the other end is open and faces the substrate silicon wafer to guide the high-speed metal vapor / plasma jet. The metal stranded wire load (7) is made of three ferromagnetic metal wires of Fe, Co and Ni. The three metal wires are of the same length, have the same number of turns and the same distance between turns. The metal wires are tightly attached to each other, which facilitates better mixing of different metal wires during the explosion and plasma process. The thin film alloy deposition substrate (8) is a single crystal silicon wafer; after obtaining a thin film with ideal characteristics, the substrate can be changed to any target object that needs to be sprayed.

5. The apparatus for synthesizing magnetic material alloy coating thin films based on the electro-explosion method as described in claim 1, characterized in that: The Helmholtz coil (9) is a pair of identical, parallel, and coaxial coils, each powered by a separate DC power supply; the coils are spaced apart by a distance of... D Exactly equal to the diameter of the coil d This ensures that a uniform and constant unidirectional magnetic field is obtained within region D. The mechanical cantilever (10) is connected to two Helmholtz coils respectively. The mechanical cantilever is equipped with a direction adjustment knob and a telescopic rod to enable the coil to adjust the axis direction within a range of no more than 90°, so as to obtain magnetic fields in different directions and facilitate the magnetization of metal nanoparticles in different directions.

6. The apparatus for synthesizing magnetic material alloy coating thin films based on the electro-explosion method as described in claim 1, characterized in that: The evacuation port (11) and the inlet port (12) are connected to the vacuum pump and the Ar gas cylinder, respectively. First, the vacuum pump evacuates the cavity to a relatively low vacuum environment, and Ar gas is filled into the cavity through the inlet port (12) to restore the cavity to atmospheric pressure. At this time, the cavity is in an Ar gas environment, which can effectively prevent the oxidation of the products of the electrical explosion.

7. A method for synthesizing magnetic material alloy coating films using the apparatus described in claim 1, characterized in that: The high-voltage electrode (2) and the ground electrode (3) are connected to the pulse source system via a coaxial high-voltage cable. The high-voltage electrode (2) is connected to the inner core of the coaxial high-voltage cable, and the ground electrode is connected to the outer sheath of the coaxial high-voltage cable. The pulse source system consists of a DC high-voltage power supply, a pulse capacitor, and a spark switch. When the DC high-voltage power supply charges the pulse capacitor to the required voltage, the pulse current flows through the high-voltage electrode (2), the ground electrode (3), and the secondary transfer electrode (5) through the spark switch, and then through the metal stranded wire load (7) to form a current loop, thereby driving the metal stranded wire to explode electrically. The material generated by the explosion forms a directional jet of metal through a semi-enclosed dielectric tube (6) and forms an alloy film on the thin film alloy deposition substrate (8). The Helmholtz coil (9) continuously provides a uniform magnetic field during the thin film deposition process. The magnetic field region covers the secondary transfer electrode (5), the semi-enclosed dielectric tube (6), the metal stranded load (7), and the thin film alloy deposition substrate (8). The mechanical cantilever (10) connected to the Helmholtz coil can rotate the coil direction, thereby controlling the direction of the magnetic field and magnetizing the metal nanoparticles in different directions during the thin film deposition process.

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